Slide operated lock for the breechblocks of firearms



March 31, 1942. CULLON 2,277,959

SLIDE OPERATED LOCK FOR THE BREEGH BLOCK OF A FIREARM Original Filed Oct. 4, 1937 2 Sheets-Sheet 1 ATTORNEY March 31, 1942. A. B. CULLON SLIDE OPERATED LOOK FOR THE BREECH BLOCK OF A FIREARM Original Fi led Oct. 4, 1937 2 sheets sheet 2 ll Z9 INVENTOR [lo/J ATTORNEY Patented Mar. 31, 1942 SLIDE OPERATED LOCK FOR THE BREECHBLOCKS OF FIREARll/IS Alexander B. Cuilon, Detroit, Mich.

Application October 4, 1937, Serial No. 167,220 Renewed June 29, 1939 11 Claims.

The present invention pertains to a lock for a breech block for a rifle of the slide or trombone type.

Hitherto it has been possible to provide a slide operated breech block lock in rifles not exceeding certain calibers and breech pressures, altho it is very desirable to have such action in rifles of high calibers.

Accordingly it is the principal object of the invention to provide a mechanism, comparing favorably in strength to the conventional bolt and lever operated rifles, of the higher calibers and especially the .30-06 and so called magnum loads, whereby rifles may be securely locked by the slide or trombone operation.

In my construction the receiver is splined and recessed to permit sliding and rotating action of the locking member. The breech block is cylindrical in shape and has securely fastened to it a guiding and driving member fitted to slide in the splined receiver to permit sliding but not rotating action to the block.

On the breech block is mounted a locking member adapted to slide in the same splined way but also rotatable in the recess so that rotation of the locking member in the recess will secure it and the block in the forward or firing position:

Such rotation of the locking member is accomplished by means of an actuating member slidably mounted in the frame and attached to the trombone or slide and having a cam groove receiving and engaging a cam tooth extending from the lower part of the locking member.

Another object of the invention is to provide a novel and effective means for moving the breech block and locking member to their forward limit and automatically bringing the lock actuating member into operation. Accordingly a pawl is provided in the sliding member to engage in the guiding member of the block to provide sliding action to the breech block. At the forward end of the block movement, the pawl drops out of engagement to permit a continued forward movement of the actuating member.

Because of the engagement of the cam tooth in the cam groove, this forward movement rotates the locking member to the locking position previously described.

The invention also provides means whereby the pawl re-engages the block on the return stroke of the slide and associated parts.

The invention is fully disclosed by way of example in the following description and in the accompanying drawings in which-- Figure 1 is a longitudinal section of the looking mechanism in locked position;

Figure 2 is a similar view of the mechanism in an unlocked and partially retracted position;

Figure 3 is a section on the line 3-3 of Figure 1;

Figure 4 is a section on the line 4-4 of Figure 2;

Figure 5 is a detached plan view of the lock operating cam and driving pawl;

Figure 6 is a bottom plan view of the lock and the block guide, and

Figure 7 is a section on the line T--'l of Figure 2.

Reference to these views will now be made by use of like characters which are employed to designate the corresponding parts throughout.

In Figures 1, 3, and others are illustrated a portion of the receiver l of the rifle mounted on a channel shaped frame 2 and enclosing the locking mechanism constituting the subject matter of this invention. Within the receiver is slidably mounted a cylindrical breech block 3. In the axis of the block is slidably mounted a firing pin 5 in the usual manner.

The rear end of the breech block is reduced in diameter as indicated by the numeral 6 in Figure 1, and on the reduced portion is rotatably mounted a locking member I, the details of which will presently be described. On the reduced portion and rearward of the member I is mounted a block driver and guide 8 secured to the block by a pin 9. The member 8 may, for practical purposes, be regarded as an integral part of the breech block a.

The inner cylindrical surface of the receiver I is formed with a series of straight and lengthwise locking ribs I0 spaced apart to form grooves I I as shown more clearly in Figures 3 and 4. The lock '1 is formed with ribs 12 adapted to slide in the grooves H. Forward of the grooves ii, the inner surface of the receiver l is formed with a recess or enlarged circumference l3 adapted to receive the ribs l2 and permit rotation of the entire locking member as will presently appear. Similarly, the block driver and guide 8 is formed with lengthwise grooves l4 receiving the ribs to and providing ribs I5 slidably received in the grooves II, as shown more clearly in Figure 4.

As already indicated, the rifle is of the trom bone or slide operated type and accordingly is provided with a pair of flat rods I8 supported for lengthwise sliding movement and connecting at the forward ends with a wooden fore piece in the usual manner. To the rear ends of the rods is attached a lock-operating cam member I! by means of a pin l8 and slidably mounted in the frame 2 as shown in Figures 1, 2, and 5. The lower rear portion of the receiver is cut away at 2 to permit the engagement of the locking member and the actuating member. The member I! is formed with a cam groove l9 receiving a similarly shaped'cam tooth 20 of less length, formed on the bottom of the lock member I.

The member [1 is bifurcated at its forward and rear ends as indicated by' the numerals 2| and 22 respectively. The forward bifurcation 2| receives one end of a pawl 23 which is pivotally mounted on the pin IS. The other bifurcation 22 receives the engaging end 24 of the pawl, the bottom of the member ll being suitably recessed at 25 to receive the body of the pawl, as may be seen in Figures 1 and 2.

The rear end of the block driver and guide member 8 is formed with a notch 26 to receive the engaging end 24 of the pawl. The sides21 of the notch diverge from the base of the notch, as shown in Figures 1 and 6, for a purpose that will presently appear.

The rotating member I on the block 6 is provided with a bevelled surface 28 on the forward end of the lower rib l2 adapted to engage and slidably rotate on the inclined surface 29 as more clearly shown in Figure 6, the purpose of which will soon appear.

In the operation of the device, let it be assumed that the'breech block 3 is about to be locked and that the breech block and associated members have been advanced to the positions shown in Figures 2 and 6. This movement has been accomplished by the rods l6 and their connection through the pawl 23 to the driver and guide 8. During this forward motion, the ribs l2 and I were slid along the grooves H- and to the position illustrated in Figure 2. The bevelled surface 28 is in engagement with the inclined surface 29, preventing further forward movement without some small amount of rotating movement. To allow for this rotating movement the rearward ends of the ribs 12 and the forward ends of the ribs H) are suitably formed to permit the lock '1 to rotate as it continues its forward movement to abutment 30. At this time the pawl 23 drops out of engagament with groove 25 in driver 8, aided by the diverging sides 21, into the recess provided for this purpose in the frame 2.

The block 3, locking member I and driver 8 are now at their farthest forward position and stopped from further sliding movement by abutment 30. The pawl being out of engagement, the sliding member I! is now permitted to move forward to its fullest extent, and in so doing the movement of the groove i9 along the cam tooth 2i] obviously turns the lock 1 to its fully locked position, with its ribs l2 in full abutment I against the ribs of the receiver as shown in Figure 3. Thus the block 3 is secured against rearward movement, as the lock 1 engages the block 3 at the forward end of the reduced portion 6 and rearward end of the large portion.

On the rearward stroke of the slide the member I1 turns the lock 1 thru its cam tooth 26] received in groove [9 of member l1, until the bevel 28 engages the inclined surface 29. Continued rotation imparts a slight rearward pull of great power to the block, the purpose of which is to loosen the exploded cartridge case in the barrel. The pawl 23 rides up the angular surface 3! and engages the guide 8 in the notch 26 so that the breech block assembly may be withdrawn to its rearward limit.

The forward end of the breech block is provided with extractors and the receiver is provided with means for ejecting the cartridge, in the usual manner. These parts, being conventional and not comprised in the invention, are not illustrated.

Although a specific embodiment of the invention has been illustrated and described it will be understood that various alterations in the details of construction may be made without departing from the scope of the invention as indicated by the appended claims.

What I claim is:

1. In a firearm, a receiver, a breech block splined therein, a locking member having a larger outside diameter than said block, rotatably mounted on and slidable with said block and splined in said receiver, said receiver having an internal recess of increased diameter permitting rotation of said locking member therein, a frame, a slidably mounted actuating member in said frame, a cam tooth and cam groove connection between said locking and actuating members,said cam tooth being of less length than said groove, and an abutment for limiting the forward movement of said breech block and of said locking member in said recess, whereby continued forward movement of said actuating member turns said locking member in said recess out of splined engagement with said receiver.

2. In a firearm, a receiver, a breech block splined therein, a locking member rotatably mounted on and slidable with said block and splined in said receiver, said receiver having an internal recess of increased diameter permitting rotation of said locking member therein, a frame, a slidably mounted actuating member in said frame, a cam tooth and cam groove connection between said locking and actuating members, said cam tooth being of less-length than said groove, and a pawl carried by said actuating member engageable with said block for bodily moving said locking member and actuating member without relative movement therebetween, an abutment for limiting the forward movement of said block and said locking member in said recess, and means for disengaging said pawl from said block when said block engages said abutment, whereby continued forward movement of said actuating member turns said lock- I ing member in said recess out of splined engagement with said receiver.

3. In a firearm, a receiver, a breech block slidable therein, a locking member supported on and slidable with said block and splined in said Mr receiver, a frame, a slidably mounted actuating member in said frame, a cam tooth and cam groove connection between said locking and actuating members, said cam tooth being of less length than said groove, and a pawl carried by said actuating member engageable with said block for bodily moving said locking member and actuating member without relative movement therebetween, and an abutment'for limiting the forward movement of said block and said locking member in said receiver, whereby continued forward movement of said actuating member turns said locking member out of splined engagement with said receiver, means for disengaging said pawl from said block when said block engages said abutment, whereby said actuating member is free to continue forwardly along said tooth. 1

4. In a firearm, a receiver, a breech block slidable therein, a locking member supported on and slidable with said block and splined in said receiver, a frame, a slidably mounted actuating member in said frame, a cam tooth and cam groove connection between said locking and actuating members, said cam tooth being of less length than said groove, and a pawl carried by said actuating member engageable with said block for bodily moving said locking member and actuating member without relative movement therebetween, and an abutment for limiting the forward movement of said block and said locking member in said receiver, whereby continued forward movement of said actuating member turns said locking member out of splined engagement with said receiver, means for disengaging said pawl from said block when said block engages said abutment, whereby said actuating member is free to continue forwardly along said tooth and means for rel-engaging said pawl with said block on the return stroke of said slide.

5. In a firearm, a receiver, a breech block slidable therein, a locking member supported on and slidable with said block and splined in said receiver, a frame, a slidably mounted actuating member in said frame, a cam tooth and cam groove connection between said locking and actuating members, said cam tooth being of less length than said groove, and a pawl carried by said actuating member engageable with said block for bodily moving said block, locking member and actuating member without relative movement therebetween, means for supporting said pawl in engagement with said block, and an abutment for limiting the forward movement of said block and said locking member in said receiver, and means for disengaging said pawl from said block when said block engages said abutment, whereby continued forward movement of said actuating member turns said locking member out of splined engagement with said receiver.

6. In a firearm, a receiver, a breech block slidable therein, a locking member supported on and slidable with said block and splined in said receiver, a frame, a slidably mounted actuating member in said frame, a cam tooth and cam groove connection between said locking and actuating members, said cam tooth being of less length than said groove, and a pawl carried by said actuating member engageable with said block for bodily moving said block, locking member and actuating member without relative movement therebetween, means for supporting said pawl in engagement with said block, and an abutment for limiting the forward movement of said block and said locking member in said receiver, whereby continued forward movement of said actuating member turns said locking member out of splined engagement with said receiver, said frame having a recess for causing said pawl to drop out of engagement with said block when said block engages said abutment, whereby said actuating member is free to continue forwardly along said tooth.

'7. In a firearm, a receiver, a breech block slidable therein, a locking member supported on and slidable with said block and splined in said receiver, a frame beneath said receiver, a slidably mounted actuating member in said frame, a cam tooth and cam groove connection between said locking and actuating members, said cam tooth being of less length than said groove, and a pawl carried by said actuating member engageable with said block for bodily moving said block, locking member and actuating member without relative movement therebetween, means for supporting said pawl in engagement with said block, an abutment for limiting the forward movement of said block and said locking member in said receiver, whereby continued forward movement of said actuating member turns said locking member out of splined engagement with said receiver, said frame having a recess for causing said pawl to drop out of engagement with said block when said block engages said abutment, whereby said actuating member is free to continue forwardly along said tooth, and means at the rear end of said recess for reengaging said pawl with said block on the return stroke of said slide.

8. In a firearm, a receiver, a breech block slidable therein, a locking member supported on and slidable with said block, said locking member having a slidable and interlocking engagement with said receiver, an actuating member slidably attached to said receiver and engageable with said locking member, and including a pawl, said pawl being engageable with said block for bodily moving said block, said locking member and said actuating member without relative movement therebetween, means for supporting said pawl in engagement with said block, means limiting the forward movement of said block in said receiver, means for disengaging said pawl when said block has reached its forward limit of movement, whereby continued forward movement of said actuating member engages interlocking surfaces of said block and said receiver, and means for re-engaging said pawl with said block on the return stroke of said actuating member.

9. In a firearm, a receiver, a breech block slidable therein, a locking member supported on and slidable with said block and splined in said receiver, a frame, a slidably mounted actuating member in said frame, a cam tooth and cam groove connection between said locking and actuating members, for rotating said locking member on relative sliding movement of said actuating member, a pawl carried by said actuating member and engageable with said block for bodily moving said locking member and actuating member without relative movement therebetween, an abutment for limiting the forward movement of said block and said locking member in said receiver, and means for disengaging said pawl from said block when said block engages said abutment, whereby continued forward movement of said actuating member turns said locking member out of splined engagement with said receiver.

10. In a firearm, a receiver, a breech block slidable therein, a locking member supported on and slidable with said block and splined in said receiver, a frame, a slidably mounted actuating member in said frame, a cam tooth and cam groove connection between said locking and actuating members, for rotating said locking member on relative sliding movement of said actuating member, slide rods connected to said actuating member for sliding the same, a pawl carried by said actuating member and engageable with said block for bodily moving said locking member and actuating member without relative movement therebetween, an abutment for limiting the forward movement of said block and said locking member in said receiver, and means for disengaging said pawl from said block when said block engages said abutment, whereby continued forward movement of said actuating member turns said locking member out of splined engagement with said receiver.

11. In a firearm, a receiver, a breech block slidabie therein, a locking member having a larger outside diameter than said block, supported on and slidable with said block and splined in said receiver, a frame, a .slidablyv with said block for bodily moving said locking member and actuating member without relative movement therebetween, an abutment for limit- .ing the forward movement of said block and said locking member in said receiver, and means for disengaging said pawl from said block when said block engages said abutment, whereby continued forward movement of said actuating member turns said locking member out of splined 1' engagement with said receiver.

ALEXANDER B. CULLON. 

